Described below is a method for the operation of a radio communication system, wherein a network-end radio station transmits information intended for a plurality of subscriber stations.
In radio communication systems, messages, for example voice information, image information, video information, SMS (Short Message Service), MMS (Multimedia Messaging Service) or other data are transmitted with the aid of electromagnetic waves via a radio interface between transmitting and receiving stations. In this case, depending on the specific configuration of the radio communication system, the stations can involve various subscriber stations or network-end radio stations such as repeaters, radio access points or base stations. In a mobile radio communication system, at least some of the subscriber stations are mobile radio stations. The electromagnetic waves are emitted with carrier frequencies that lie in a frequency band provided for the respective system.
Present-day mobile radio communication systems are often embodied as cellular systems e.g. according to the standard GSM (Global System for Mobile Communication) or UMTS (Universal Mobile Telecommunications System) with a network infrastructure including e.g. base stations, devices for controlling the base stations and further network-end devices. A further example is broadband networks having wireless access for example in accordance with IEEE 802.16. Future mobile radio communication systems may be e.g. further developments of UMTS, referred to as LTE (Long Term Evolution), or fourth-generation systems, and also ad hoc networks. Apart from wide-area organized (supralocal) cellular, hierarchical radio networks, there are wireless local area networks (WLANs) having a radio coverage area that is generally spatially delimited to a significantly greater extent. Examples of various standards for WLANs are HiperLAN, DECT, IEEE 802.11, Bluetooth and WATM.
In radio communication systems, subscriber stations' access to the shared transmission medium is regulated by multiple access (MA) methods/multiplex methods. In the case of these multiple accesses, the transmission medium can be divided among the subscriber stations in the time domain (Time Division Multiple Access, TDMA), in the frequency domain (Frequency Division Multiple Access, FDMA), in the code domain (Code Division Multiple Access, CDMA), or in the space domain (Space Division Multiple Access, SDMA). Combinations of multiple access methods are also possible, such as e.g. the combination of a frequency division multiple access method with a code division multiple access method.
In the downlink direction, that is to say from a network-end radio station to subscriber stations, information can be transmitted via point-to-point channels to individual subscriber stations or via point-to-multipoint channels simultaneously to a plurality of subscriber stations. Examples of services wherein a plurality of subscriber stations are addressed simultaneously by one message are DVB-H (Digital Video Broadcasting-Handhelds), DMB (Digital Multimedia Broadcasting) and MBMS (Multimedia Broadcast Multicast Service).